We should switch the keyboard layout to the layout the user set according to

chromeos/ime/input_method_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMEOS_IME_INPUT_METHOD_MANAGER_H_
 #define CHROMEOS_IME_INPUT_METHOD_MANAGER_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 80 matching lines @@
   // Returns all input methods that are supported, including ones not active.
   // This function never returns NULL. Note that input method extensions are NOT
   // included in the result.
   virtual scoped_ptr<InputMethodDescriptors>
       GetSupportedInputMethods() const = 0;
 
   // Returns the list of input methods we can select (i.e. active) including
   // extension input methods.
   virtual scoped_ptr<InputMethodDescriptors> GetActiveInputMethods() const = 0;
 
+  // Returns the list of input methods we can select (i.e. active) including
+  // extension input methods.
+  // The same as GetActiveInputMethods but returns reference to internal list.
+  virtual const std::vector<std::string>& GetActiveInputMethodIds() const = 0;
+
   // Returns the number of active input methods including extension input
   // methods.
   virtual size_t GetNumActiveInputMethods() const = 0;
 
   // Changes the current input method to |input_method_id|. If |input_method_id|
   // is not active, switch to the first one in the active input method list.
   virtual void ChangeInputMethod(const std::string& input_method_id) = 0;
 
   // Enables keyboard layouts (e.g. US Qwerty, US Dvorak, French Azerty) that
   // are necessary for the |language_code| and then switches to |initial_layout|
   // if the string is not empty. For example, if |language_code| is "en-US", US
   // Qwerty, US International, US Extended, US Dvorak, and US Colemak layouts
   // would be enabled. Likewise, for Germany locale, US Qwerty which corresponds
   // to the hardware keyboard layout and several keyboard layouts for Germany
   // would be enabled.
   // This method is for setting up i18n keyboard layouts for the login screen.
   virtual void EnableLayouts(const std::string& language_code,
                              const std::string& initial_layout) = 0;
 
   // Activates the input method property specified by the |key|.
   virtual void ActivateInputMethodProperty(const std::string& key) = 0;
 
   // Updates the list of active input method IDs, and then starts or stops the
   // system input method framework as needed.
   virtual bool EnableInputMethods(
       const std::vector<std::string>& new_active_input_method_ids) = 0;
 
+  // Adds one entry to the list of active input method IDs, and then starts or
+  // stops the system input method framework as needed.
+  virtual bool EnableInputMethod(
+      const std::string& new_active_input_method_id) = 0;
+
   // Remaps old input methods like "mozc" to new input methods. Return true if
   // at least one IME is migrated.
   // TODO(nona): Remove this function after few milestones are passed.
   //             (http://crbug.com/236747)
   virtual bool MigrateOldInputMethods(
       std::vector<std::string>* input_method_ids) = 0;
   virtual bool MigrateKoreanKeyboard(
       const std::string& keyboard_id,
       std::vector<std::string>* input_method_ids) = 0;
 
@@ skipping 40 matching lines @@
 
   // Switches the current input method (or keyboard layout) to the next one.
   virtual bool SwitchToNextInputMethod() = 0;
 
   // Switches the current input method (or keyboard layout) to the previous one.
   virtual bool SwitchToPreviousInputMethod() = 0;
 
   // Switches to an input method (or keyboard layout) which is associated with
   // the |accelerator|.
   virtual bool SwitchInputMethod(const ui::Accelerator& accelerator) = 0;
+
+  // If all input methods of a given language can be used at login screen
+  virtual bool IsLanguageFullLatinKeyboard(const std::string& lang) const = 0;
 };
 
 }  // namespace input_method
 }  // namespace chromeos
 
 #endif  // CHROMEOS_IME_INPUT_METHOD_MANAGER_H_